Abstract

A description is given of a 1‐meter focus vacuum grating spectrometer for the infra‐red which is distinguished by its versatility and compactness of design. The vacuum container is tubular in form and all optical parts are mounted on a carriage which is readily retractable from the case for adjustment. A novel feature is the use of a sine screw drive which gives a linear wave‐length scale. A representative spectrum tracing is given.